


Magnus, How Long Have You Been Twenty?

by Master of Unlocking (Hikarinimichitasora)



Category: Mortal Instruments Series - Cassandra Clare, Shadowhunters (TV)
Genre: M/M, Soulmate AU
Language: English
Status: Completed
Published: 2016-03-02
Updated: 2016-03-02
Packaged: 2018-05-24 08:10:41
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,429
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/6147298
Author URL: https://archiveofourown.org/users/Hikarinimichitasora/pseuds/Master%20of%20Unlocking
Summary: <blockquote class="userstuff">
              <p>Soulmate AU where you age to about 18/21, and then you stay that age until you find your soulmate.</p>
            </blockquote>





	Magnus, How Long Have You Been Twenty?

**Author's Note:**

> Written for the ficathon at LJ: http://ladygawain.livejournal.com/83265.html?thread=928065#t928065

"How long have you been twenty Magnus?"

Magnus didn't want to answer that question. The answer was too damn long. Every time he'd thought he'd got it right, he only had to wait a few years to see that he hadn't aged a day. His lovers would leave and his heart would break just a little more. But this girl who liked to play with danger was asking him, a flirtatious smile on her face. She was alluring, but she wasn't enchanting. Besides, he felt she probably wasn't the kind to hang and help him with his centuries of insecurities.

"How long have you been?" he replied. Isabelle smiled easily.

"I will never fall in love," she announced. "I'll be young forever."

Magnus couldn't imagine anything worse but without revealing the answer, he could hardly chastise her for her desire. She couldn't have been twenty long, watching her parents grow older and older as she remained youthful, her friends growing laughter lines and stretching skin around their waistlines from the happiness they had found with another.

"Perhaps that is how long I've been twenty? Forever does have a nice, vague ring to it," he sipped his drink.

 _Cocktails, of course_.

This soiree was the kind where everything was served potently and expensively. He expected nothing less of the Lightwood family. He had been rather surprised that he had been invited, however. They usually kept those they considered... _controversial_  out of the equation. He guessed they had needed him on the guest list for one reason or another though he wasn't yet sure what that reason could be.

"Well, you are as charming as they say you are, I suppose," Isabelle replied and he could see that she enjoyed the game of flirting just as much as he did. He gave her a brief smile.

"You should see me when I'm really trying to fluster you," he replied. "I have been known to-"

"Isabelle!"

Both of them looked up. The man walking towards them looked perhaps eighteen or nineteen. He probably hadn't reached the point where he stopped aging yet though Magus couldn't say for sure. He was tall, wiry and dark. He had a pair of startlingly blue eyes that made Magnus think of [butterfly pea flowers](https://upload.wikimedia.org/wikipedia/commons/7/78/Clitoria_ternatea_butterfly_pea_flower_at_Bhadrachalam_02.JPG) that his mother had grown in their garden when he was young. He glanced at Isabelle beside him, to see she was giving him a smug look.

"Alec, may I introduce you to Magnus Bane?" Isabelle said when he had reached them. ' _Alec_ ' barely glanced at Magnus before he took Isabelle's elbow. Magnus guessed that this must be her brother, Alexander Lightwood.

"Mother's going nuts. You're supposed to stay by her side," Alexander said, his voice low. The hairs on the back of Magnus' neck stood up.

_Oh, dear, dear Isabelle, so that had been your game? Well, I can play along I suppose._

"I assume you're Alexander Lightwood? A pleasure," Magnus said, reaching out his right hand, palm down. He could see Alexander warring with two desires. The first, to keep hold of his sister so that he could escort her wherever she was meant to be. The second, to not appear rude in front of a guest. Eventually, the latter won out and Alexander reached out his hand to awkwardly try to shake Magnus' own.

"Magnus Bane. I've heard a lot about you," he said, and that voice was just perfection.

_How long since I took a lover of my own? How long since I tried to love someone? Took a chance? Ten years? Twenty?_

He couldn't recall. Long enough that the thrill of excitement running down his spine was making him giddy.

_I appear to have developed an instantaneous crush._

"Oh, I'm sure it was only good things," Magnus replied, allowing a flirtatious smile. "The rumors of my debauchery are _greatly_ exaggerated... Well, most of them anyway."

Alexander stared at him blankly for a few moments, as though he wasn't sure what to do with that information. He didn't appear to have any kind of attraction to Magnus, but the way Isabelle was looking between them made him think that perhaps she, at least, suspected her brother wasn't straight.

"I... Well, that's..." Alexander finally stammered. Magnus reached up and patted his cheek.

"It's alright. I suppose if you've got a pretty face, you don't really need to be able to form a complete sentence," he said. Alexander frowned a little, confused, and stepped away.

"Isabelle, Mother-" He began again. Isabelle nodded her head, her smile stretched from ear to ear.

"Alright. I'll leave you to give Magnus the grand tour. I promised him I was going to but if Mother needs me..." Isabelle began to walk away. Magnus watched her brother's face with interest. Although his face seemed impassive, there was a hint of panic in his eyes. Truly, they were exquisitely expressive.

"Why don't we start with the gardens? It's a warm night, is it not?" Magnus suggested. Alexander was still watching his sister's back as she sashayed through the crowd. "Or we could start with your bedroom I suppose. But I thought you might be the kind to take it slow."

Alexander seemed to finally hear him then and turned, his face once more adorably confused. Magnus resisted the urge to pat his cheek again.

"Wh-what?" he asked, folding his arms in front of him defensively.

"I asked to see the gardens, Alexander," Magnus said and he saw the way that Alexander swallowed when he used his name.

_I could have a lot of fun playing with this Lightwood boy._

"I... It's dark. There's nothing to see out there," Alexander replied. Magnus sighed. It seemed the boy was either dense or playing disgustingly hard to get.

"I see. Well, we can observe it from a balcony... or a window I suppose," he said, gesturing out of the lounge and towards a door that he hoped lead outside. Alexander seemed to finally have no more objections and began to walk away. Magnus followed, necking his cocktail.

_Lord save me from virginal Lightwood boys, they are all so dense..._

* * *

 

Outside, Alec tried to catch his breath. Magnus was stood incredibly close. Closer than was needed, if they were honest. The balcony gave a decent view of the gardens. What the lights from inside didn't illuminate, the moon did instead. The light was pale blue and it made the dew on the grass sparkle like... glitter. Like the glitter, that was lining Magnus' eyes.

_I do not want to think about how Magnus' eyes look right now._

"Well, your landscaper really did a wonderful job. You'd have never known this used to be farmland," Magnus said, waving his hand around dismissively. Alec looked at him out of the corner of his eye. Everyone knew Magnus Bane had been around a long time, longer than his parents, and he had never found the one that would help him age. Yet it wasn't possible that he remembered the manor's earliest stages. That was hundreds of years ago. There was no way that anyone could wait that long for their soulmate before going insane.

"I don't know anything about the landscaping, sorry," he replied. He hoped he could leave now. Something about Magnus made him feel uncomfortable. Perhaps it was that the man was... so comfortable with who he was. Alec had heard the rumors. That in his pursuit of love and happiness, Magnus had hunted on both sides of the fence. Alec was only just coming to terms with the fact he had been hunting on the wrong side all along, and even then he wasn't sure how to tell his parents that he believed his soulmate was going to be a man.

He knew that they would suggest that he find a woman to continue the family line before the chance came that he might meet him.

"You don't seem like the type to garden, anyway. And neither am I, truth be told. I'm much more of a city dweller-" Magnus continued talking and Alec tried to tune him out as best he could. He was afraid. He hoped that Jace was his soulmate. They had grown up together. If over the next few years they continued growing, then Alec would know that they were meant to be together. He was willing to risk his family's censure for that opportunity. He wouldn't risk a relationship with Jace on a passing... flirtation with Magnus Bane.

"Why are you here?" Alec asked finally, interrupting Magnus mid-sentence. The other tilted his head to the side, seemingly puzzled.

"I was invited here," he replied and didn't offer any more explanation than that.

_Did I expect him to give a truthful answer?_

"If you're just here to scout out new talent, I have to say that you might have better luck elsewhere. Nearly everyone here's who's of age has already met you once," Alec said, deciding that the harsh truth now was better than a harsher one later. Magnus smiled and put his empty glass down on the balcony railing.

"But I have met someone new, have I not?" he asked. Alec scowled. He was being far too forward.

"Me and my sister-"

"Alec, there you are!"

Alec turned when he heard Jace's voice. Magnus followed his line of sight. Jace came through the balcony doors. Behind him stood a beautiful red-haired girl who looked politely confused.

"Who're you talking to out here? I was going to introduce you to someone. Her name's Clary. She's Jocelyn Fray's daughter. Come on, you have to meet her," Jace said, clapping him on the shoulder. Alec cleared his throat, aware that Magnus was watching him closely.

"Er, yeah. Sure. Clary, right?" Alec said, nodding along. He could feel himself heating up under Magnus' stare but he told himself he had nothing to be ashamed of. If Magnus could see his attraction to Jace, maybe he'd leave him alone after all? "Er, Magnus, it's been nice to meet you."

Magnus leaned against the balcony and looked between the two of them once more.

"The pleasure has been all mine, Alexander. Now go, Clary is a delight. I'm sure you'll like her," he said, waving his hand towards the party inside. Jace grinned at him and pulled him away. Alec got almost to the door before he could no longer fight the urge to look back. When he did, though, he saw that Magnus had turned to face the night's sky and was no longer looking at him.

* * *

"And that's everything for your health check, Mr. Bane," the doctor said, her smile in place. Magnus held the cotton wool against the hole in his arm where she'd taken his blood. No doubt the tests would be done shortly and he could leave. Even though he had long since been out of the game of sleeping around, he still made sure to get himself screened once a year. It would never do to be sick without knowing it.

"Okay, the results of the first part of your test can be told to you straight away... You're still a healthy weight... Your blood pressure is fine..." the doctor read from the screen. "Your age is twenty years, six months and fifteen days."

Magnus felt his chest constrict.

"What did you say?" he asked. The doctor frowned and double checked she was on the right screen.

"Yes, your bloodwork... it's coming back placing you at... a different age to the last time you were here," she said. She began to type rapidly. "It seems like... you met your soulmate four months and five days ago. Congratulations Mr. Bane!"

Magnus sank back onto the examination bed. Four months and five days ago had been the party at the Lightwoods. It had been the day he'd met Alexander. It had been the day he'd allowed himself the thrill of a crush for the first time in years and then found out that in the end, that crush was more interested in another. Had there been anyone else there? Perhaps it was the delightful Isabelle?

But in his gut, Magnus knew. He knew it was the Lightwood boy.

"You do not look happy," the doctor said, sounding concerned.

"Oh dear, you don't know the half of it."

* * *

"What do you mean, you're older?"

Alec paused outside the door to Jace's room. He could hear his mother inside. She sounded concerned, her voice raised slightly above normal decibel level. He could hear her shoes on the ground as she paced.

"I... thought that it might be the case. I thought that I'd met my soulmate so I got the age test done. There's no doubt about it. I'm older," Jace replied. Alec swallowed. Was it true? If it was, did that mean that he was older too? He needed to get it checked. He needed to know if it were him.

"And who is the person who set off this reaction?" Alec heard his mother ask. Jace was silent for a moment.

"I think it's... Clary Fray," he said. Alec felt his stomach plummet to his shoes. That... that couldn't be true.

"You're sure?" Maryse asked. Alec couldn't see them but he was sure that Jace nodded because the next voice was his mother's one.

"I suppose congratulations are in order, then. Once I see confirmation of both of your tests, of course," she said. Alec backed away from the door. It couldn't be possible. Clary? She barely knew Jace! They had known each other only a few months and how was it even possible that they became close enough to think that they needed to take the soulmate tests?

"Alec, what are you doing-"

Alec's head snapped up. Isabelle had come out of her room and seen him. He heard his mother's shoes on the floor of Jace's bedroom. He immediately felt trapped, constricted, and did the only thing he could think of. He ran away.

* * *

 

The phone rang once, twice, then picked up.

"Isabelle Lightwood, at your service."

Magnus sighed. He had hoped to get Alexander directly, but his sister would probably be able to find him just as easily. She might even be able to trick or cajole him onto the phone.

"I'm sure you are. Magnus Bane, I'm calling to speak to your brother," he said, trying not to sound too desperate. Isabelle let out a delighted laugh.

"Of course, you are. And I'm sure Alec wants to speak to you, but he's a little... lost right now," she said. Magnus frowned.

"Lost?" he repeated. "Your house is big but I would have thought that by age eighteen or so you'd have worked out where all the rooms were?" Again, that delightful laughter cut short by the sound of clipped heels on marble.

"Is that Alec?"

 _Ah, the equally clipped tones of Maryse Lightwood. Charming_.

"Er, no, Mother. It's... Magnus Bane," Isabelle said. Magnus grimaced. He was almost certain what was about to happen and he had no desire to listen to incensed maternal rage.

"Magnus... Right, I see. Ask him if he's seen Alec," Maryse demanded. He heard Isabelle take a breath to pass the message along but cut in before she could ask.

"I last saw Alexander four months and five days ago... give or take a few hours," he said. There was a long pause before Isabelle relayed the information to her mother. There was an even longer pause after that.

"One son to the Frays, the other to _Magnus Bane?_ I can't deal with this right now. Isabelle, hang up. Our most important priority right now is finding Alec," Maryse said.

"I'm sorry, Magnus. I wish I could help you. I'll call you when he's found, okay?" she said. Magnus didn't have time to reply before she hung up on him. He stared at the phone in his hand.

* * *

 

It was the wedding of the year. His parents had invited everyone. Everyone except Magnus Bane that was. Alec straightened his tuxedo. In his pocket was the wedding ring. He was best man, of course. But also, there was a slip of paper. He'd taken the test the day that he'd found out that Jace and Clary were officially soulmates. It confirmed only one thing. He'd met his own soulmate already, and that his time was passing slowly but surely. He'd been slowly adding days, weeks, months to the slip of paper. It had been eighteen months and fourteen days since he'd met the person he was destined to be with.

And that meant it couldn't be Jace, even if he found it hard to believe. He had kept a sharp handle on his emotions, determined not to let anything show that might alert Jace to his turmoil. His mother and Isabelle had found him, eventually, and brought him home. He had told them it was brotherly jealousy, that he had thought that he and Jace had years together yet, but he knew that Isabelle saw straight through him. She didn't mention anything about Jace though.

No, all she wanted to talk about was Magnus Bane.

It seemed that the other man had called the house, that day when he wasn't there. He'd said something that made Isabelle determined that they should meet again. Although Alec knew she was only doing what she thought was right, he also knew that no quick tryst with someone like Magnus Bane was going to cure him of this ailment.

He double-checked his pocket again, making sure the ring was definitely there.

The door opened.

He thought it would be Isabelle, come to check in on him, but it wasn't. Magnus Bane stood there, dressed in a tuxedo that would have made his mother grimace at its flashiness. Alec felt something in his stomach squirm.

"Well, you look handsome," Magnus said, stepping into the room and closing the door.

"I thought you weren't invited," Alec replied. Magnus let out a low chuckle.

"Ah, yes, Magnus Bane the wedding crasher. Don't worry, I'll be gone before your mother even knows I was here. This is just a disguise so I could get in here," he said. Alec couldn't see how something so flamboyant could have anything to do with espionage, but then, he wasn't Magnus Bane. He had no idea how the other's mind worked.

"Why are you here then?" he asked. Magnus took a few steps closer until he was almost uncomfortably inside Alec's personal space.

"Did you know that there's a way to test if you're soulmates without taking medical tests?" Magnus asked. Alec frowned.

"No, there isn't," he said. Magnus smirked.

"You're right. I was just hoping to steal a kiss. You see, here's the thing. Eighteen months and fourteen days ago, I met my soulmate. Briefly, I'll admit. We didn't talk much. But destiny doesn't care. It's started my clock, as it were, and I'm loathe to die alone while he gets himself together," Magnus said, the amusement still on his face but beneath it a hint of sincerity that made Alec's chest feel heavy. He swallowed.

"You must be mistaken if you think-"

"I had given up on love. Just like you, I know what it's like to be in love with someone and then to find out that they've met their fated one. I know what it's like to congratulate them as they walk up that aisle," Magnus said, and for a moment, there was a look on his face, something lost and bitter and vulnerable. Alec had seen the expression before, on his own face, in the mirror, that very morning.

"Imagine the pain it is to know that someone is your fated, but they insist on not seeing you anyway? Tell me, did your mother screen my calls, or did you just never call me back?" Magnus asked. Alec's throat felt dry.

"I... You called?" he asked. He needed Magnus to move away. His thoughts felt scrambled. He was about to watch the man he _loved_ get married. He didn't have time for this-

"I called and I called and I called. You see, I've been waiting a very long time to meet you, Alexander," Magnus continued. Alec felt his heart speed up. No one called him Alexander anymore, but the way Magnus said it... it was almost reverent.

"I... I have to go. It's Jace's wedding and I'm best man. If I'm late-"

Magnus looked him up and down, straightening his bow tie before stepping back.

"I won't give up, Alexander. If you won't do my test, then you should get the medical one. If the times match up... It would be foolish to fight it," he said. Alec bit down on the inside of his cheek to stop himself from replying. Instead, he walked out of the room.

_Damn, Magnus Bane. Damn him._

It wouldn't even matter, but Alec could feel his heart racing, could feel his heated cheeks, could feel the squirming sensation in his stomach.

 _Damn Magnus Bane because he's_ right _!_

* * *

 

Magnus lounged on the couch. He'd done all he could, but still he couldn't help but feel it wasn't enough. Even so, he wouldn't force Alexander to do anything. He couldn't. He didn't want someone bound to him because some arbitrary fate had said it had to be so. Unless Alexander really was prepared to love him, what would be the point? He didn't want to be resented. He could imagine nothing worse.

And seeing him in person again. _That_ had been something unexpected. He'd been so beautiful, more beautiful than Magnus remembered. In the morning light of that room, it had been like the world had stopped for a moment. But even if the world refused to move for him, it had moved for everyone else. Alexander had left without even promising to see him again, and their time together decreased more and more the longer the other fought it.

His doorbell rang.

Tiredly, Magnus dragged himself to his feet. He pressed the buzzer to let in whoever it was and took the catch off the door. He hoped that it wasn't Camille. He couldn't deal with her right now. He opened the door and waited for the elevator to bring his guest up to the penthouse floor.

The elevator pinged and Alexander stepped out. For a moment, Magnus just stared at him. Alexander Lightwood stood in the doorway of his apartment. His tuxedo was more mussed than it had been that morning. He'd let his bow tie dangle around his neck rather than leaving it done up. He looked perfect.

"We need to talk," Alexander said and Magnus stepped aside to let him in wordlessly. Alexander seemed uncomfortable as he stepped over the threshold but he said nothing. He made a beeline for the couch and sat down on it before he jumped to his feet again.

"Oh no, please, sit, sit," Magnus said, going into host mode. "Can I get you a drink? I'll let you know, I make the best Mary Pickfords-"

"I... Whatever is fine, really," Alexander said. Magnus took it in his stride and walked to the liquor cabinet, pouring himself and Alexander healthy measures of alcohol into their glasses. He had been sure that Alexander would refuse. The fact that he did not... did it mean that he intended to stay here longer than a few minutes?

"How was the wedding? Was the bride beautiful?" Magnus asked, shaking the alcohol over the ice before serving it in the long-stemmed glasses he'd laid out. Alexander nodded.

"Yeah... She looked... fantastic. Jace looked happy too. It went well," he said. Magnus tried not to be jealous about the hint of wistfulness in the other's voice. It didn't matter that Alexander was in love with Jace if he was here now.

"I'm glad for all of you," Magnus replied, finally picking up the drinks and taking them to where Alexander sat. He made sure their hands brushed as he handed over the glasses.

"Eighteen months and fourteen days. That's when I met my soulmate," Alexander blurted out. Magnus felt his breath catch. "I did the test a year ago. I just... I couldn't accept it. Not until today. Not until I saw them. Not until I saw you again."

Magnus sat down on the couch. He drained his glass. He wished he'd brought a bottle of something hard with him. It wasn't right to have to do this conversation sober.

"You accept that you're my soulmate?" he asked. Alexander cleared his throat.

"Yes," he said though his voice still wavered a little.

"Then we should start dating, I suppose," Magnus replied. Alexander looked surprised.

"Wh-what? But we're soulmates! Soulmates don't date!" he protested. Magnus smiled, leaning back on the couch.

"Oh, and what do soulmates do, exactly? Instantly file the wedding papers and start having babies together?" he asked. Alexander looked confused and Magnus had to admit it was adorable.

"Well... yes. I mean, we can't have babies but usually, soulmates don't bother with-"

"You are adorable. But you're also wrong. Soulmates can date, and take things slow and get to know each other," Magnus said. Alexander sipped his drink. Even though it wasn't that strong, he still grimaced at the taste. _Truly a novice at all life's vices._

"You want to... _go out_ with me?" he asked. Magnus wondered how far he could push it.

"Well, to start with that would be good. Then it'll probably lead to kissing and from there to heavy petting and after that, maybe even-"

"Alright, alright, I see where you're going with this," Alexander said, his face suddenly beet-red. Magnus chuckled.

"At the moment, I find you physically attractive and your personality is adorable. I want to get to know you better," Magnus explained. "Regardless of being soulmates, I would have always wanted that."

Alexander was silent for a long time. Magnus watched the emotions pass over his face. Fear, excitement, doubt, worry, bravery, resolution. Alexander eventually rubbed at his forehead before looking up, a small, shy smile spreading over his face.

"So is this our first date then?" he asked. Magnus laughed, feeling delighted, and stood up.

"It can be. Let's drink cocktails and play truth or dare. I've heard it's all the rage with you _young ones_ ," he said, winking and going to refill his glass. Alexander frowned.

" _Young ones_...? Magnus, how long have you been twenty?" he asked. Magnus didn't turn around, a smile pulling at his lips.

"Over three hundred years, Alexander. All just to wait for you."

 

 


End file.
